Multi-sectional nut and adjustable length pole incorporating such nut

ABSTRACT

A nut assembly for quick adjustment of axial position relative to a threaded shaft. The nut is formed in two, physically separate sections, each having a surface portion with threads for mating engagement with the shaft. Each nut section is pivotally mounted to a bushing which surrounds the threaded shaft for movement of the nut threads into and out of engagement with the shaft threads. The sections are moved about their pivotal mountings by movement of a second bushing axially with respect to the first bushing through cooperative conical surfaces on the second bushing and on each of the nut sections.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a divisional of and claims priority toApplicant's U.S. patent application Ser. No. 11/017,260, filed Dec. 20,2004, now U.S. Pat. No. 7,198,236, the entirety of which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to nuts having a plurality of sectionsmovable into and out of threaded engagement with a threaded rod, as wellas to poles having telescopingly engaged sections utilizing such nuts topermit rapid adjustment of the overall length of the pole.

U.S. Pat. No. 4,498,204 of Stanley H Warner and U.S. Pat. No. 5,826,847of Stanley H. Warner and Terry P. Warner, the latter being the presentapplicant, disclose pole assemblies primarily intended for physicalsupport of infirm or handicapped persons, i.e., to assist such personsin rising, standing, etc. by providing a sturdy support member formanual grasping at a desired location. The poles include telescopingsections permitting adjustment of the overall length of the pole and forfixing the relative axial positions of the sections at a desired point.The later of the two patents includes a multi-section nut for movementof the sections between a first position, wherein the internal threadson the nut sections engage the external threads on an elongated shaftwhich is fixed to and extends axially through one of the hollow polesections, and a second position, wherein the nut threads are releasedfrom threaded engagement with the shaft. When the nut sections areengaged with the threads on the shaft, the sections of the pole arefixed to prevent relative axial movement, and when the threads on thenut sections and the shaft are disengaged the pole sections may be movedaxially relative to one another to change the overall length of the poleas desired.

One of the objects of the present is to provide a nut assembly wherein aplurality of nut sections may be moved between engaged and disengagedpositions with respect to an elongated, threaded shaft in a simple andexpeditious manner with reliable operation of a minimal number ofruggedly constructed components.

Another object is to provide a pole assembly including a plurality oftelescoping sections for selective adjustment of the overall length ofthe pole and incorporating in the pole structure a multi-section nut ofthe improved design disclosed herein to permit relative, linear, axialmovement of pole sections for rapid adjustment to an approximate,desired overall length, and actuation of nut components to engage athreaded shaft forming a portion of the pose assembly for relative,rotational, axial movement of pole sections for more precise control ofoverall pole length.

Other objects will in part be obvious and will in pat appearhereinafter.

SUMMARY OF THE INVENTION

In the disclosed embodiments, the nut assembly of the invention includesa bushing having a central, through bore. Mounted upon the bushing aretwo, identical, elongated legs, each having a first and a second end. Atone end the legs are supported for pivotal movement upon dowels passingthrough openings in the bushing and the legs, with the legssubstantially parallel to the central axis of the bushing. At the otherend, the legs have inner surface portions formed with portions ofthreads facing the central axis, and outer surface portions which areangularly disposed with respect to the central axis. A single coilspring is positioned within the bushing with one end engaging acounterbore in the bushing and the other end engaging a shoulder on eachof the legs to bias the latter toward movement in a first directionabout their pivotal mountings.

The nut is designed for movement of the pivot legs between first andsecond positions, wherein the threaded, inner surface portions are inand out of threaded engagement with a shaft passing coaxially throughthe bushing. When the threads on the pivot legs engage the threads onthe shaft, the bushing, and other structure with which it may beassociated, such as the adjustable pole disclosed herein, may be axiallymoved upon the shaft by relative rotation of the bushing and shaft. Whenthe legs are moved to disengage the threads on the legs from those onthe shaft, the entire nut assembly may be freely moved axially withrespect to the shaft. As in the two referenced patents, this permitsrapid movement of the nut assembly, and any associated structure, to anapproximate, desired, axial position upon the shaft and thereafter afinal adjustment to the desired position by rotating the nut assemblyupon the shaft.

The nut assembly is disclosed in two embodiments, in both of which thepivot legs are moved between their first and second position by axialmovement of a second bushing with respect to the first-mentionedbushing. The second bushing has a conical surface which engages thesurface potions on the pivot legs which are angularly disposed withrespect to the coaxial, central axes of the bushings and shaft. In afirst embodiment, the first and second bushing are not mutually,physically connected and are relatively moved linearly, withoutrotation, for engagement of the cooperable surfaces on the secondbushing and the pivot legs to move the threaded surface portions of thelegs into engagement with the threads on the shaft. In a secondembodiment, the first and second bushings are threadedly engaged withone another, and axial movement of the conical surface of the secondbushing is effected by relative rotation of the two bushings.

The first embodiment of the nut assembly is shown in association withthe pole structure to form a composite assembly wherein the nut isincorporated in an article advantageously employing the adjustablefeatures of the not.

The structure and operation of the invention will be more readilyunderstood and fully appreciated from the following detailed disclosure,taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, perspective view of a first embodiment of the nutassembly of the invention;

FIG. 2 is a front elevational view of the elements of FIG. 1 in sectionand in assembled condition;

FIG. 3 is an exploded, perspective view of a second embodiment of thenut assembly;

FIG. 4 is a front elevational view of the elements of FIG. 3 in sectionand in assembled condition;

FIG. 5 is an exploded, perspective view of an adjustable pole assemblyin association with the first embodiment of the nut assembly; and

FIGS. 6 and 7 are fragmentary, front elevational views, in section andin assembled condition, of the pole and nut assemblies of FIG. 5,showing threaded portions of the nut assembly in and out, respectively,of threaded engagement with a central shaft of the assembly.

DETAILED DESCRIPTION

The nut assembly of the invention is shown in a first embodiment inFIGS. 1 and 2, to which attention is initially directed. Bushing 10 hasa through bore 12 with central axis A-A and a pair of axially elongated,through slots 14, 14′ on opposite sides. A pair of identical, elongatedlegs 16, 16′ each have first (18, 18′) and second (20, 20′) ends,respectively. Openings 22, 22′ extend through legs 16, 16′,respectively, adjacent ends 18, 18′, and openings 24, 24′ extend thoughbushing 10, parallel to one another and on opposite sides of axis A-A,on both sides of slots 14, 14′. Dowel pins 26, 26′ extend with force fitinto openings 24, 24′ in bushing 10 and with slip fit through openings22, 22′ in legs 16, 16′, whereby the legs are supported in slots 14, 14′for pivotal movement with respect to bushing 10.

Adjacent ends 20, 20′, legs 16, 16′ have external surface portions 28,28′ and internal surface portions 30, 30′, respectively. Surfaceportions 28, 28′ form portions of a conical plane concentricallysurrounding axis A-A, while surface portions 30, 30′ are cylindrical inform and each is tapped to provide a set of threads. A single coilspring 32 is positioned within bushing 10 and seated at one end uponannular shoulder 34, formed as a counter-bore in bore 12, and at theother end upon shoulders 36, 36′ of legs 16, 16′, respectively. Thus,spring 32 exerts a biasing force tending to move legs 16, 16′ abouttheir respective pivotal mountings with ends 20, 20′ moving away fromaxis A-A. The extent of such pivotal movement of the legs is limited bycontact of side edges of the legs with opposing side portions of slots14, 14′.

The nut assembly of FIG. 1 is shown in FIG. 2 in association withthreaded shaft 38. The threads on shaft 38 are formed for matingengagement with the threads on inner surface portions 30, 30′ of legs16, 16′. Thus, when legs 16, 16′ are rotated in the direction of bias byspring 32, inner surface portions 30, 30′ and the threads thereon arespaced outwardly from shaft 38 and its threads, permitting free relativeaxial movement of bushing 10 and shaft 38. When legs 16, 16′ are rotatedagainst the biasing force of spring 32 to move ends 20, 20′ toward oneanother, the threads of inner surface portions 30, 30′ engage thethreads on shaft 38, permitting relative axial movement of bushing 10and shaft 38 in response to relative rotational movement of the bushingand shaft.

Although various means may be employed to effect movement of legs 16,16′ between the positions wherein the threads on the legs are engagedand disengaged with the threads on shaft 38, including manually movingthe legs when the nut assembly is employed in applications permittingmanual access to the legs, the device shown in the illustrated versionis second bushing 40. Shaft 38 extends through axial bore 42 of bushing40 and surface 44, in the form of a truncated cone, encircles one end ofbore 42. Outer surface portions 28, 28′ of legs 16, 16′ are, aspreviously described, conical and complementary with conical surface 44.Thus, when first and second bushings 10 and 40, respectively, are movedaxially toward one another, surface 44 engages surface portions 28, 28′and continued movement produces rotation of legs 16, 16′ about pins 26,26′ to move the threads of surface portions 30, 30′ into engagement withthe threads on shaft 38. Upon movement of bushings 10 and 40 away fromone another, the legs are rotated by the bias of spring 32 to disengagethe threads. Thus, the bushings may be moved freely with respect to theshaft to bring bushing 10 to an approximate, desired position upon theshaft, whereupon the threads on the pivotal bushing legs are placed inengagement with the threads on the shaft and more precise positioning ofthe bushing on the shaft is effected by relative rotation of the bushingand shaft. Bushing 40 includes a pair of flanges 41 and 43 between whichis a portion of reduced diameter. Flanges 41 and 43 are provided for apurpose described later in connection with an application wherein thenut assembly of FIGS. 1 and 2 is employed in an adjustable poleassembly.

Turning now to FIGS. 3 and 4, the nut assembly is shown in an embodimentwherein the two bushings are relatively moved to actuate the pivot legsby rotation rather than by direct, linear movement, as in the firstembodiment. The same reference numerals are used in FIGS. 3 and 4 as inFIGS. 1 and 2 for elements common to the two embodiments, although somemay be of alternate forms. For example, bushing 10 is made from roundstock in the first embodiment and hex stock in the second, although bothhave the same axial bore with counterbore to support the same coilspring, as well as the same slots wherein the same legs are pivotallymounted. In the second embodiment, bushing 10 is internally threadedwithin a portion 45 of bore 12 surrounding ends 20, 20′ of legs 16, 16′,respectively. Second bushing 40 is externally threaded over portion 46of its length and provided with a knurled surface over portion 48.Conical surface 44 again surrounds bore 42 and coacts with surfaceportions 28, 28′ in effecting rotation of legs 16, 16′. Although inwardmovement of ends 20, 20′ of the legs to bring the threads on the legsand shaft into mutual engagement is effected by relative axial movementof first and second bushings 10 and 40, respectively, the axial movementis effected by relative rotational movement of the two bushings in thesecond embodiment.

The nut assembly of FIGS. 1 and 2 is shown in a practical application inFIGS. 5 through 7, in association with a pole of adjustable overalllength. The pole is formed by three, hollow, telescopingly engaged rods,termed for convenience upper rod 50, intermediate or push-up rod 52 andlower rod 54, although it will be understood that the pole may beemployed in orientations other than vertical. Other terms, such as top,bottom, upwardly, etc. are used consistently with a vertical orientationof the pole. Bushing 56 is secured to plate 58 by wing bolt 60 and isfixedly attached, by welding or other means, to rod 50 within the upperend thereof. The upper end of shaft 38 is affixed to bushing 56 andextends coaxially through upper rod 50. Bottom plate 62 is formedintegrally with lower rod 54. Bushing 10 is fixedly attached to push uprod 52, extending into the upper end thereof, and second bushing 40extends into the upper end of lower rod 54 and is fixedly attachedthereto. Set screw 63 extends through threaded opening 65 in push up rod52. As seen in FIG. 6, set screw extends into the reduced diameterportion of bushing 40, between flanges 4 and 43, without contactingbushing 40, thereby limiting relative axial movement of bushing 40 andpush up rod 50, and preventing excessive movement of push up rod 52relative to the assembly of lower rod 54.

The elements are shown in FIG. 6 with push up rod 52 and lower rod 54positioned so that conical, outer surface portions 28, 28′ of legs 16,16′ rest upon conical surface 44 of bushing 40, thereby rotating thelegs to bring the threads on legs 16, 16′ into engagement with thethreads on shaft 38. In this position, rod 52 may be rotated while rods50 and 54 remain stationary, thereby rotating bushing 10 upon stationaryshaft 38 to move upper rod 50 axially with respect to push up rod 52 andlower rod 54. This movement changes the overall length of the pole by arelatively small increment, providing the final adjustment of the pole.For larger increments of pole length adjustment, push up rod 52 isgrasped and lifted upwardly a small distance (after using the threadedconnection to remove upper plate 58 from engagement with an opposingsurface) while bottom plate 62 and bushing 40 remain stationary. Pivotleg surfaces 28, 28′ are thus removed from contact with surface 44 ofbushing 40, allowing spring 32 to rotate legs 16, 16′ outwardly todisengage the threads on the legs with those on shaft 38.

Upper rod 50 may then be freely moved relative to lower rod 54, thuschanging the overall length of the pole and the spacing between upperand lower plates 58 and 62, respectively.

From the foregoing, it will be seen that the nut assembly of theinvention provides all the advantages of quick adjustment along thelength of a threaded shaft in either large or small increments. The nutis formed in a plurality of physically separate sections, each having asurface portion which is threaded for movement into and out ofengagement with the shaft. The nut sections are pivotally mounted on abushing which surrounds the threaded shaft and, among the means whichmay be employed to transmit movement to the nut sections, there isdisclosed a second bushing which is moved axially relative to the firstbushing either by direct, linear movement or by rotational movementthrough threaded connection of the first and second bushings.

The nut assembly is disclosed in a typical application wherein it isemployed in an adjustable length pole, such as that of preciouslyreferenced U.S. Pat. No. 5,826,847. The nut assembly and pole of thepresent invention decrease manufacturing cost and improve the functionsof the prior patent. The single coil spring of the present nut assemblyurges the threaded nut sections toward movement away from engagementwith the threaded shaft, providing a reverse bias compared to the twosprings of the prior patent. This allows the nut assembly to operate aspart of the intermediate, push-up rod instead of as part of the lowerrod, as in the prior patent. This is advantageous because the push-uphollow rod is of greater diameter than the lower rod, thereby providingmore usable space for augmenting the functions of the nut sections. Thisfeature also lessens the expense and increases rigidity of the lower rodassembly, because the lower rod is welded or otherwise fixed directly tothe bottom plate, rather than requiring rotation of the lower rodrelative to the plate as in the prior patent. The present design alsoprovides better primary alignment of the threaded shaft and bushings, atypically equiring less rotational force in threading operationsinvolving the engaged thread components.

1. A nut assembly for cooperative operation with an externally threadedshaft having a first diameter and a first, central axis, said nutassembly comprising: a. a first bushing having a first, through bore ofsecond diameter, so as to be larger than said first diameter and havinga second, central axis, and at least two slots formed therethrough; b. asecond bushing located at least partially inside said first bushing andhaving a second, through bore of third diameter, so as to be larger thansaid first diameter and having a third, central axis, said first andsecond bores configured to have the shaft extend therethrough with saidfirst, second and third axes coaxial; c. at least two, physicallyseparate sections each having a first surface portion formed with threadportions configured to be mateable with the thread of said shaft; d.means for pivotally attaching said sections to said first bushing,wherein each of said sections is positioned within a respective one ofsaid slots and is moveable about said pivotally attaching means betweenfirst and second positions within the respective one of said slots, andwherein said surface portion of each of said sections is configured tobe spaced radially outwardly from said shaft, and in threaded engagementwith said shaft, respectively; and e. each of said sections having asecond surface portion cooperable with a third surface portion of saidsecond bushing for movement of said sections between said first andsecond positions thereof in response to relative axial movement of saidfirst and second bushings.
 2. The nut assembly of claim 1 and furtherincluding means for biasing said sections toward movement to said firstpositions thereof.
 3. The nut assembly of claim 2 wherein said biasingmeans comprises a single spring connected to both of said sections. 4.The nut assembly of claim 1 wherein said sections are elongated, havingfirst and second ends and pivotally connected to said first bushingadjacent said first end and having said first surface portion adjacentsaid second end.
 5. The nut assembly of claim 1 wherein said first andsecond bushings are physically unconnected to one another and saidrelative axial movement is effected by direct, relative, linear movementof said first and second bushings.
 6. The nut assembly of claim 1wherein each of said first surface portions extends less than 180degrees about a pitch circle concentric with said first and secondbushings.
 7. The nut assembly of claim 1 wherein each of said second andthird surface portions are conical and configured to be concentric withsaid second, central axis when assembled with said externally threadedshaft.
 8. A nut assembly comprising: a. a first bushing having a firstthrough, axial bore of first diameter and having a first central axisand at least two slots formed therethrough; b. at least two elongatedlegs each having a surface portion formed with thread portions, whereineach of said legs is positioned within a respective one of said slotssuch that each of said surface portions is configured to extend intosaid first axial bore; and c. means for pivotally mounting said legsupon said first bushing for movement of said legs between a firstposition within the respective one of said slots, wherein said threadportions of each of said surface portions are spaced a first distanceoutwardly of said first central axis, and a second position within therespective one of said slots, wherein said thread portions of each ofsaid surface portions are spaced a second distance outwardly of saidfirst central axis; and d. a second bushing located at least partiallyinside said first bushing and having a second, through bore of seconddiameter, so as to be larger than said first diameter and having asecond, central axis, said first and second axes coaxial.
 9. The nutassembly of claim 8 wherein said legs are mounted on diametricallyopposite sides of said first bushing for movement of said surfaceportions toward and away from one another as said legs are moved betweensaid first and second positions.
 10. The nut assembly of claim 9 whereineach of said sections includes a first end and a second end, saidsurface portion being adjacent said first end and said pivotallymounting means being adjacent said second end.